Integrated servo-mechanical design using Nyquist plots for chance-constrained robust mechatronics

Integrated servo-mechanical design is commonly solved using numerical methods. In this paper, allowable regions for the redesigned open loop Nyquist plot are derived based on performance and chance-constrained robust stability specifications, considering high-frequency reshaping of the mechanical plant based on a low-order controller. Our simulation results on the Pb-Zr-Ti active suspension in a commercial 3.5" dual-stage hard disk drive achieve a single-stage feedback control system with guaranteed disturbance attenuation capabilities and robust stability.